1. Field of the Invention
This invention relates generally to the production of wheel trim and more particularly to a system and method for reducing costs and increasing production efficiency in the manufacture of diverse molded plastic wheel covers having a common mounting system.
2. Background History
Molded plastic wheel covers have gained widespread acceptance as both OEM equipment and as stable aftermarket lines. Among the acknowledged advantages of molded plastic wheel covers were corrosion resistance, light weight, the ability to be painted to match or compliment vehicle color and the ability to be plated to simulate metal wheels.
The versatility and durability of molded plastic wheel covers has been such that they have been virtually universally accepted as the standard alternative to cast metal wheels in OEM new vehicle applications and have additionally captured the bulk of the aftermarket.
A variety of mounting and retention systems have been utilized for plastic wheel covers including a metal grip ring seated in a channel, as disclosed in U.S. Pat. No. 3,876,257, issued to the assignee of the present invention, retention clips seated in hollow sockets, such as disclosed in U.S. Pat. No. 4,523,789 and grip fingers which were outwardly spring biased by a wire band, as illustrated in U.S. Pat. Nos. 4,822,109 and 3,480,329.
A further example of plastic wheel cover mounting systems was exemplified in U.S. Pat. No. 4,998,780 which disclosed lug nut caps, carried by a wheel cover, and threaded on exterially threaded portions of wheel lug nuts.
With automotive manufacturers constantly striving for consumer acceptance through first impression styling i.e., by presenting vehicles with attractive and unique appearance, there was a demand for OEM suppliers to have production capability for multiform wheel cover styles which were all mountable to the same size wheel and utilized the same mounting system. Unfortunately, each wheel style required a completely new mold assembly. As such, significant capital costs were attributable to each different wheel cover style.
Additionally, for each model year changeover, completely new wheel cover mold tooling was required and sufficient lead time was necessary to complete such tooling.
A significant proportion of mold tooling costs, in terms of mold design and fabrication labor, were attributable to the mounting system rather than the aesthetic styling of the wheel cover itself.